In the field of packaging food and non-food pumpable and/or flowable products, a convenient method of packaging such products in thermoplastic film has been developed and is generally known as a form-fill-seal process. In such a process a tube is formed from thermoplastic film and the bottom end seal is made by transversely sealing across the tube with heated seal bars to form a conveniently wide heat seal and, consequently, producing a pouch ready to receive a product. After the heat seal is made, the pouch is filled and then another transverse heat seal is made across the width of the tube in a relatively wide band. This seal is transversely severed to separate the filled pouch from the next pouch to be filled. Thus, one wide band seal serves as the bottom seal for one pouch and the top seal for another.
Vertical form/fill/seal (VFFS) packaging systems have proven to be very useful in packaging a wide variety of flowable products. An example of such systems is the Onpack.TM. flowable food packaging system sold by W. R. Grace & Co.-Conn. through its Grace Packaging group. The VFFS process is known to those of skill in the art, and described for example in U.S. Pat. No. 4,589,247 (Tsuruta et al), U.S. Pat. No. 4,656,818 (Shimoyama et al.), U.S. Pat. No. 4,768,411 (Su), and U.S. Pat. No. 4,808,010 (Vogan), all incorporated herein by reference in their entirety. A flowable product is introduced through a central, vertical fill tube to a formed tubular film having been sealed transversely at its lower end, and longitudinally. The pouch is then completed by sealing the upper end of the tubular segment, and severing the pouch from the tubular film above it. The patents noted above describe a two stage process where the creation of a transverse heat seal occurs at one stage in the process, and then, downstream of the first stage, a separate pair of cooling/clamping means contact the just-formed transverse heat seal to cool and thus strengthen the seal.
More recently, a VFFS process has been developed wherein the upper transverse seal of a first pouch, and the lower transverse seal of a following pouch, are made, and the pouches cut and thereby separated between two portions of the transverse seals, without the need for a separate step to clamp, cool, and cut the seals. A commercial example of an apparatus embodying this more simplified process is the Onpack.TM. 2050A VFFS packaging machine marketed by the Grace Packaging Division of W. R. Grace & Co.-Conn.
Several ways of dispensing the contents of such pouches at their point of use, such as a restaurant, commissary, or the like, have been proposed. One is the use of an internal fitment sealed to the interior surface of a pouch wall, such as the Asept.TM. fitment distributed in the U.S. by W. R. Grace & Co.-Conn. through its Grace Packaging group, and disclosed in U.S. Pat. No. 4,603,793 (Stern). In use, a coupling device would be inserted through the pouch material to communicate with the internal fitment, and a conventional dispensing device would be connected to the coupling device for delivering measured portions of the contents of the pouch.
An alternative technique and apparatus for dispensing the contents of a pouch is the use of a pouring spout such as the Top-Tap.TM. pouring spout supplied by DuPont Canada, and described in differing embodiments in their Canadian Patent No. 1,192,164 (Obidniak) and U.S. Pat. No. 5,325,995 (Harrison et al). This system involves piercing the filled pouch with the sharp end (piercing nozzle) of a pouring spout, and driving the piercing nozzle into the pouch interior until the laminate forming the pouch wall engages the shoulder of the piercing nozzle. When this occurs, the plastic material forming the pouch will dispose around the shoulder of the nozzle, to be secured by a collar. The pouring spout can then be used to dispense the contents of the pouch.
In some cases, a packager may wish to forgo the use of internal or external fitments because of the additional packaging cost associated with such devices.
An alternative is simply to cut open the pouch with a knife at the time that the contents of the pouch are to be placed in a dispenser. However, this procedure, although simple, exposes the user to the possibility of injury when cutting open the pouch. Even if the cutting/opening operation is done without injury, this procedure leaves the choice of where to cut the pouch to the worker, which can cause spillage of the contained product. Additionally, for insurance reasons, many restaurants, such as some fast food outlets, do not permit knives or the like in the food preparation area of the restaurant.
It would thus often be desirable to avoid the necessity of using fitments, and the haphazard use of a knife or other sharp object to open the pouch, and to provide that the pouch could be simply and easily torn open at a preselected point on the pouch, chosen to make the opening process easier and reduce potential spillage.
However, many VFFS and other packaging applications require the use of packaging materials, especially flexible packaging materials, that can be used to package food or non-food articles and protect these articles during storage and distribution. Where flowable foods are packaged, as in many VFFS applications, the hydrostatic pressure of many oil and water based foods, and the high temperatures at which some foods are packaged, require a tough, impact and abuse resistant packaging material that will maintain its structural integrity during the packaging process, and subsequent distribution and storage. Film technology has progressed to the point where many films offer a high degree of abuse resistance. In addition, the heat seals of pouches made by this process are of flattened, relatively strong and tough thermoplastic film made even stronger and tougher by the fact that the seals form a two-ply heat welded band. Unfortunately, the same properties of toughness and abuse resistance that are desirable for the performance of the packaging material in protecting the contained article, often make it difficult or impossible for the end user to manually open the package without the aid of a knife or the like.
Various solutions to this problem have been proposed with a view to overcoming this problem and making it easier to open packages of the type just described, including the use of tear notches, perforations, slits, etc. which guide the user to a particular place on the pouch to initiate tear.
However, current systems for creating a tear notch in a VFFS system have relied on an additional knife that is affixed to a ribbed sealing bar, the bar used to create the transverse seals of each package. This knife projects from the face of the seal bar in a rigid, immovable arrangement, and is attached to the seal bar by set screws or the like. When the seal bar is activated by being heated and brought into contact with the pouch material, the knife simultaneously contacts and cuts the material that is being sealed, thereby severing the pouch material. Unfortunately, when used to make packages on a VFFS packaging machine, such a system sometimes leads to loosening of the set screws or other affixing devices as a result of the normal operation of the equipment. This in turn can result in the knife falling out of the sealing bar, thereby disrupting the packaging process. In a food processing facility, where VFFS systems are frequently employed, this disruption can cause economic loss to the processor, who must shut down the machine to recover the knife, and replace the knife in the sealing bar. This can also jeopardize the integrity of the packaged product, in the event that the knife falls inside a filled pouch. Finally, care must be used by the operator during routine cleaning of the seal bar, to avoid injury from the exposed knife.
It would therefore be of great benefit to the packaging industry to provide a method and apparatus that are compatible with current commercial packaging systems; operate independently of the seal bar; simultaneously cut the tube to provide a pouch, and cut an easy open tear notch in a transverse seal; and simultaneously provide an easy open tear notch in an upper transverse seal of a first package, and an easy open tear notch in a lower transverse seal of a second package above the first package.